package com.popay.common.utils;

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

public class AesUtil4 {

    private static final String KEY_ALGORITHM = "AES";
    private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";// 默认的加密算法
    private static final String KEY = "oGglQaaem16JDZr9ismX0A==";
    private static final String CHARSET = "utf-8";


    /**
     * AES 加密操作
     *
     * @param content 待加密内容
     * @param key     密钥
     * @return 返回Base64转码后的加密数据
     * @throws NoSuchPaddingException
     * @throws NoSuchAlgorithmException
     * @throws UnsupportedEncodingException
     * @throws InvalidKeyException
     * @throws BadPaddingException
     * @throws IllegalBlockSizeException
     */
    public static String encryptStr(String content) throws NoSuchAlgorithmException, NoSuchPaddingException, UnsupportedEncodingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

        Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);// 创建密码器

        byte[] byteContent = content.getBytes(CHARSET);

        cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(KEY));// 初始化为加密模式的密码器

        byte[] AjaxJson = cipher.doFinal(byteContent);// 加密

        return Base64.encodeBase64String(AjaxJson);// 通过Base64转码返回

    }

    /**
     * AES 解密操作
     *
     * @param content 待解密内容
     * @param key 密钥
     * @param charset
     * @return
     * @throws NoSuchPaddingException
     * @throws NoSuchAlgorithmException
     * @throws InvalidKeyException
     * @throws BadPaddingException
     * @throws IllegalBlockSizeException
     * @throws UnsupportedEncodingException
     */
    public static String decryptStr(String content) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {

        // 实例化
        Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
        // 使用密钥初始化，设置为解密模式
        cipher.init(Cipher.DECRYPT_MODE, getSecretKey(KEY));
        // 执行操作
        byte[] AjaxJson = cipher.doFinal(Base64.decodeBase64(content));
        return new String(AjaxJson, CHARSET);

    }

    /**
     * 生成加密秘钥
     *
     * @return
     * @throws NoSuchAlgorithmException
     */
    private static SecretKeySpec getSecretKey(final String key) throws NoSuchAlgorithmException {
        // 返回生成指定算法密钥生成器的 KeyGenerator 对象
        KeyGenerator kg  = KeyGenerator.getInstance(KEY_ALGORITHM);

        // AES 要求密钥长度为 128
        SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
        secureRandom.setSeed(KEY.getBytes());

        kg.init(128, secureRandom);

        // 生成一个密钥
        SecretKey secretKey = kg.generateKey();

        return new SecretKeySpec(secretKey.getEncoded(), KEY_ALGORITHM);// 转换为AES专用密钥

    }

    public static void main(String[] args) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, UnsupportedEncodingException, IllegalBlockSizeException, BadPaddingException {

        String aa = AesUtil4.encryptStr(System.currentTimeMillis()+"周天宇");

        System.out.println(aa);

        System.out.println(AesUtil4.decryptStr(aa));

    }

}
